When hazardous liquid and solid materials are loaded into a transport tank for storage and shipping the materials often evolve a vapor or gas which are highly objectionable because of odor, flammability and/or toxicity. Often these vapors or gases include hydrogen sulfide and mercaptans which are extremely toxic to the environment.
As these materials are loaded into a transport tank the air within the tank including any vapor or gas that has evolved from the material is displaced from the tank and vented to the atmosphere. It is undesirable to directly vent this gas to the atmosphere due to obvious environmental concerns and to the risk of explosion from the gas being ignited.
There exist small scale gas scrubbing devices that are installed in line with the gas vent of the transport tank for the purpose of venting small amounts of evolved gas during transport. An example of such a device is described in Canadian published application no. CA2120899. Drawbacks to these devices include the limited volume of gas that may be scrubbed before having to replace the scrubber, the relative low flow rates within which they are operable, and being externally disposed and at risk to damage. Because of these drawbacks, these devices are not suitable for scrubbing gas vented during loading of the transport tank, and rather, they are better suited to scrubbing lower volumes of gas that are evolved from the material during actual transport.
Another gas scrubbing device includes a bath of liquid through which evolved gases are bubbled up so that harmful constituents may be reacted with the liquid and removed from the gas prior to venting. Liquid bath scrubbers have numerous drawbacks that have prevented wide adoption of their use. These drawbacks include the risk of spilling the liquid and thus creating an environmental hazard, having to frequently test the liquid for strength, and the relative high head pressures that must develop within the transport tank before any gas is able to pass through the liquid bath.
Accordingly, there is a need for a new gas scrubber that overcomes the disadvantages discussed above and other inherent disadvantages existing in currently available gas scrubbers.